[PATCH v4 2/2] clk: samsung: gs101: propagate PERIC1 USI SPI clock rate

From: Tudor Ambarus
Date: Fri Apr 19 2024 - 06:09:58 EST


When SPI transfer is being prepared, the spi-s3c64xx driver will call
clk_set_rate() to change the rate of SPI source clock (IPCLK). But IPCLK
is a gate (leaf) clock, so it must propagate the rate change up the
clock tree, so that corresponding MUX/DIV clocks can actually change
their values. Add CLK_SET_RATE_PARENT flag to corresponding clocks for
all USI instances in GS101 PERIC1: USI{0, 9, 10, 11, 12, 13}. This change
involves the following clocks:

PERIC1 USI*:

Clock Div range MUX Selection
-------------------------------------------------------------------
gout_peric1_peric1_top0_ipclk_* - -
dout_peric1_usi*_usi /1..16 -
mout_peric1_usi*_usi_user - {24.5 MHz, 400 MHz}

With input clock of 400 MHz this scheme provides the following IPCLK
rate range, for each USI block:

PERIC1 USI*: 1.5 MHz ... 400 MHz

Accounting for internal /4 divider in SPI blocks, and because the max
SPI frequency is limited at 50 MHz, it gives us next SPI SCK rates:

PERIC1 USI_SPI*: 384 KHz ... 49.9 MHz

Which shall be fine for the applications of the SPI bus.

Note that with this we allow the reparenting of the MUX_USIx clocks to
OSCCLK. Each instance of the USI IP has its own MUX_USI clock, thus the
reparenting of a MUX_USI clock corresponds to a single instance of the
USI IP. The datasheet mentions OSCCLK just in the low-power mode
context, but the downstream driver reparents too the MUX_USI clocks to
OSCCLK. Follow the downstream driver and do the same.

Fixes: 2999e786d7e9 ("clk: samsung: gs101: add support for cmu_peric1")
Reviewed-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
Acked-by: André Draszik <andre.draszik@xxxxxxxxxx>
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
---
drivers/clk/samsung/clk-gs101.c | 90 ++++++++++++++++++---------------
1 file changed, 48 insertions(+), 42 deletions(-)

diff --git a/drivers/clk/samsung/clk-gs101.c b/drivers/clk/samsung/clk-gs101.c
index 76d4d0fa1168..bd3c1b02715b 100644
--- a/drivers/clk/samsung/clk-gs101.c
+++ b/drivers/clk/samsung/clk-gs101.c
@@ -3239,47 +3239,53 @@ static const struct samsung_mux_clock peric1_mux_clks[] __initconst = {
MUX(CLK_MOUT_PERIC1_I3C_USER,
"mout_peric1_i3c_user", mout_peric1_nonbususer_p,
PLL_CON0_MUX_CLKCMU_PERIC1_I3C_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI0_USI_USER,
- "mout_peric1_usi0_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI0_USI_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI10_USI_USER,
- "mout_peric1_usi10_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI10_USI_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI11_USI_USER,
- "mout_peric1_usi11_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI11_USI_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI12_USI_USER,
- "mout_peric1_usi12_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI12_USI_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI13_USI_USER,
- "mout_peric1_usi13_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI13_USI_USER, 4, 1),
- MUX(CLK_MOUT_PERIC1_USI9_USI_USER,
- "mout_peric1_usi9_usi_user", mout_peric1_nonbususer_p,
- PLL_CON0_MUX_CLKCMU_PERIC1_USI9_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI0_USI_USER,
+ "mout_peric1_usi0_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI0_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI10_USI_USER,
+ "mout_peric1_usi10_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI10_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI11_USI_USER,
+ "mout_peric1_usi11_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI11_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI12_USI_USER,
+ "mout_peric1_usi12_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI12_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI13_USI_USER,
+ "mout_peric1_usi13_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI13_USI_USER, 4, 1),
+ nMUX(CLK_MOUT_PERIC1_USI9_USI_USER,
+ "mout_peric1_usi9_usi_user", mout_peric1_nonbususer_p,
+ PLL_CON0_MUX_CLKCMU_PERIC1_USI9_USI_USER, 4, 1),
};

static const struct samsung_div_clock peric1_div_clks[] __initconst = {
DIV(CLK_DOUT_PERIC1_I3C, "dout_peric1_i3c", "mout_peric1_i3c_user",
CLK_CON_DIV_DIV_CLK_PERIC1_I3C, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI0_USI,
- "dout_peric1_usi0_usi", "mout_peric1_usi0_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI0_USI, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI10_USI,
- "dout_peric1_usi10_usi", "mout_peric1_usi10_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI10_USI, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI11_USI,
- "dout_peric1_usi11_usi", "mout_peric1_usi11_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI11_USI, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI12_USI,
- "dout_peric1_usi12_usi", "mout_peric1_usi12_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI12_USI, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI13_USI,
- "dout_peric1_usi13_usi", "mout_peric1_usi13_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI13_USI, 0, 4),
- DIV(CLK_DOUT_PERIC1_USI9_USI,
- "dout_peric1_usi9_usi", "mout_peric1_usi9_usi_user",
- CLK_CON_DIV_DIV_CLK_PERIC1_USI9_USI, 0, 4),
+ DIV_F(CLK_DOUT_PERIC1_USI0_USI,
+ "dout_peric1_usi0_usi", "mout_peric1_usi0_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI0_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
+ DIV_F(CLK_DOUT_PERIC1_USI10_USI,
+ "dout_peric1_usi10_usi", "mout_peric1_usi10_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI10_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
+ DIV_F(CLK_DOUT_PERIC1_USI11_USI,
+ "dout_peric1_usi11_usi", "mout_peric1_usi11_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI11_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
+ DIV_F(CLK_DOUT_PERIC1_USI12_USI,
+ "dout_peric1_usi12_usi", "mout_peric1_usi12_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI12_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
+ DIV_F(CLK_DOUT_PERIC1_USI13_USI,
+ "dout_peric1_usi13_usi", "mout_peric1_usi13_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI13_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
+ DIV_F(CLK_DOUT_PERIC1_USI9_USI,
+ "dout_peric1_usi9_usi", "mout_peric1_usi9_usi_user",
+ CLK_CON_DIV_DIV_CLK_PERIC1_USI9_USI, 0, 4,
+ CLK_SET_RATE_PARENT, 0),
};

static const struct samsung_gate_clock peric1_gate_clks[] __initconst = {
@@ -3314,27 +3320,27 @@ static const struct samsung_gate_clock peric1_gate_clks[] __initconst = {
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_1,
"gout_peric1_peric1_top0_ipclk_1", "dout_peric1_usi0_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_1,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_2,
"gout_peric1_peric1_top0_ipclk_2", "dout_peric1_usi9_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_2,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_3,
"gout_peric1_peric1_top0_ipclk_3", "dout_peric1_usi10_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_3,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_4,
"gout_peric1_peric1_top0_ipclk_4", "dout_peric1_usi11_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_4,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_5,
"gout_peric1_peric1_top0_ipclk_5", "dout_peric1_usi12_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_5,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_6,
"gout_peric1_peric1_top0_ipclk_6", "dout_peric1_usi13_usi",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_6,
- 21, 0, 0),
+ 21, CLK_SET_RATE_PARENT, 0),
GATE(CLK_GOUT_PERIC1_PERIC1_TOP0_IPCLK_8,
"gout_peric1_peric1_top0_ipclk_8", "dout_peric1_i3c",
CLK_CON_GAT_GOUT_BLK_PERIC1_UID_PERIC1_TOP0_IPCLKPORT_IPCLK_8,
--
2.44.0.769.g3c40516874-goog